Telephonic-current reinforcer or repeater system.



No. 845,282. PATENTED FEB. 26, 1907.

N. G. WARTH. I

TELBPHONIG CURRENT REINPOECER OR RBPEATBR SYSTEM. APPLICATION FILED APB.23,1906.

Qvwentoz QXWmew Nathaniel Guwwrtb am I g, mu. 6. @M. w M

ttozwnp signals and telegraphic or composite service 'rocal telephone-repeaters adapted to re- UNTTED NATHANIEL G. WARTH,

OF COLUMBUS, OHIO.

Specification of .LI

" etters Patent. Patented Feb. 26, 1907.

Application filed April 23, 1906. Serial No. 313,192.

To a, whontz't puny concern:

Be it known that I, NATHANIEL G. WARTII, l a citizen of the United States, residing at Columbus, in the county of Franklin and 1 State of Ohio, have invented certain new and useful Improvements in Telephonic-Current i Reinforcer or Repeater Systems; and I do hereby declare the following to be a full, i clear, and exact description of the invention, l such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in telephone-current repeaters or relay-reinforcers of the general character illustrated l in the following patents, to wit: Nos. 542,657 and 542,659 to Richards, Nos. 542,618, 542,619, and 542,913 to Arnold, and Nos. 791,655 and 791,656 to Shreeve.

This invention has for its chief objects the provision of a thoroughly practicable repeater system for use in connection with repeater apparatus in which the receiving element is locally maintained in a positive delicate and very sensitive to line troubles or imperfect conditions of circuit, apparatus,

' and currents not in gocd balance. Hence with the apparatus heretofore in use great care has been necessary in the selection of well-balanced lnduction-coils and repeatmgcoils to secure perfect balancing of current effects in the location, installation, and handling of the same, and particularly as to the condition and handling of the circuits thereto connected. Each wire of the pair has had to be balanced with its mate and each circuit .or section of the circuit with its other side. These conditions have been so exacting that to prevent the apparatus from setting up the local action which causes what is commonly called howling the American Telephone and Telegraph Company, now utilizing the only practicable telephone-repeater appara tus, has found it necessary to install the re peaters midway in or between long sections of circuit at stations, which if not midway the circuits or sections of same have had to be balanced artificially or specially to bring balance or hcutral stat-e regardless of any about an approximate midway location or unbalanced condition in the line-circuit or sections of circuit connected.

By my present arrangement the receiver is made sensitive or responsive to the inducing-currents from the lines, but irresponsive and insensitive to its own transmitter currents or effects. L provide apparatus and circuit arrangement whereby the reproduced retransmitted currents are maintained-in practically a distortionless form and not interfered with, confused, or mutilated by the originating currents reacting upon the repeater nor penetrating injuriously into the receiving side of the system, and, further, a simplified apparatus and circuit system of a preferred form in which the receiver and transmitter elements of the repeater proper are included in a combination local or primary circuit, and also apparatus and circuit arrangements in connection with the aforesaid conditions to effect a flexible use of the same telephonically and to also enable to be operated over the same wires without mutual interference as freely as is usual with no repeater in the circuit.

All automatic or electromechanical recip transmit with renewed energy an attenuated voice-current have heretofore, when at all practical or commercial, been extremely balance. The apparatus has thus been applied specially to a given circuit arranged to meet these peculiar and more or less diiiicult conditions.

The confusing interferin reacting eflects referred to aboveand whic cause oistorted or mutilated retransmission, and which it is one of my chief objects to prevent, are the actions upon the receiver of the repeater produced by the counter-currents set up by electromagnetic coils in the preceding forms of telephonic repeaters, which 0011s are either directly in the line-circuit at the repeater-station or are coils otherwise associated with the repeater apparatus which are energized by the original currents simultaneously with the repeater-receiver, and which, in discharging electromagnetically,

create counter or reactive currents similar in form to but out of phase with the original currents. In generat these detrimental, echohke, extra, or reaction currents are neither in the direction nor in time or step with the retransmitted currents and in pro portion to their strength have power to oppose, and thus to reduce or to improperly accentuata or to blur the retransmitted or renewed currents, resulting in a degraded transmission. are transmitted across the repeater into the associated line-circuit or section of line-cir- When the original currents cuit, or such reaction currents are set up even in the local repeater-circuit and can stronglyreact upon the repeater, imperfect anld lower transmitting efficiency is the resu t.

The local action which causes howling, referred to above, is also inherent in all previous forms of telephonic repeaters, for the reason that the receiver element has always short-circuited, crossed with another circuit, or otherwise unbalanced, even when the repeater is placed in a midway lo cation or balance'on the through-circuit, the repeater will set up the local howl, producing interfering effect. In the later forms of repeaters or repeater systems, or those in which neutralizing effects have been attempted, this condition also has not been overcome, and any line trouble or unbalanced condition which ordinarily would not cause the line to be withdrawn from service causes the repeaters to become noisy and necessitates their disconnection from the line until it is restored to its previous good con v dition.

, An unbalanced line or line-section causes an unequal flow of the difierential equalizing repeated currents from the line-circuits through the coils operating the receivertransmitter, letting the current in one direction through the controlling-coils affect the receiver to operate it, which in turn actuates the transmitter in its normal manner, send ing out an impulse to the line-circuit, and this impulse, due to the unbalanced condition, reacts upon the system, setting up a continuous vibrant musical tone having the fundamental pitch of the armature whether the latter be in the form of a diaphragm or in the form of a-plunger, or otherwise.

in describing this invention reference will be had to the drawing which accompanies and forms a part of this specification. Said drawing is a diagrammatic. representation. of my repeater for securing the improved results hereinbefore described, the repeater being shown in simple bridged relation to'a through-circuit, and the receiver-transmitter elements and associated auxiliaryapparatus included, together with the primary of the repeating induction-coil contained in the bridge in a ccmbination primary circuit.

The drawing shows my preferred arrange ment. It can be installed for use in connection with-ordinary switchboard service irrespective of lengths of circuit or circuit-sea tions connected for repeater purposesv and regardless of line-balances with reference to their affecting the repeater or the repeater affecting them inan adverse manner. It will be understood that modifications or equivalents of this form of the system and apparatus arrangements can be made without departing from the scope and intent of this invention. In this prei erred arrangement the line-wires are devoid of coils, :being'connected straight through, thus rovidin'g' a clear'and unobstructed circuit or compositedf. or

phantornec currents, as well aster the talking-currents, the bridged connection H,

with its induction coil O'secondary, (andcondensers J when necessary for'cemposite work,) being. the medium for receiving from and transmitting to the line-circuit the tele-,

phonic or talking currents. the dine-induction coil C is split or divided and is cooperatively connected into the split gimary circuit B. B containing the battery transmitter M, receiver T, and condenser I, which latter is connected aroundone coilot the receiver. 3 The receiver element has two windings that are differently acted upcn by the battery-current, which flows simultaneously through them and reduces a"neutral' magnetic state. "As the ow ofcurrent from the half B of the induction-coil C primary is caused to return through the battery '13 branch or'leg of the primary circuit the receiver would also be neutral to the incoming alternating currents from the line. Hence I I. shunt the receiver-coil, say, on the side B with the condenser I to preserve its sensi tiveness to these currents.

The action or operation is indicated com ventionally by the arrows, which show the flow of both the primary and the secondary currents, the former by the solid and the latter by thebreken' arrows. A current pulsation from originating-station S arrivingat the bridgeH with its low-impedance secondary coil C is practically all shuntedthrcugh the bridge and acting inductively The primary of These currents, being set up in the two'primary halves of the inductioncoil G, are caused to fiow cooperatively from the junction with the battery B,-branch outwardiy to and through the twoou'tside legs of the local circuit (see the broken arrows) "to and through the B side of winding receiver T and through, the condenser l on the B side oi. the.

B in the two halves B B receiver T, respectively, combining at the juncture with the transmitter M, thence flow ing through said transmitter, battery B, and the battery B branch of the circuit back to the aforesaid junction of the split primary win ding with the battery B branch, thus completing the circuits and compelling the operation of receiver T by the energized coil on the B side. The operation of the receiver ele ment T-actuates the transmitter element M to vary its resistance and set up the conse- I quent primary current effects from battery of the primary circuit. As the flow of this battery-current is difierential or opposed through the two windings of the receiver element T' (see the solid arrows) andcooperative in the primary windings of the'repeating-coil C, the current divides at the junction-points, as it did in the case of the receiving-current described above, the actionsbeing similar except that both coils of the receiver element T are energized by this current. Hence thereceiver element T is neutral orinactive, and the primary of 0011 C is active, as in the other case, andtransforms the reproduced reinforced currents which are transmitted both ways on the linecircuitfromthe secondary ofcoilG in the bridge. By reason of my elimination of coils from the line-circuit properin this arrangement' very clear and desirable conditions of circuit with repeater service are provided for the talking-currents, as well as for the various forms of composite, simplex, and fphantom-circuit" transmission. N0 interfering reactive-current eflects are-set ,up, as there is in circuit only the line-repeating induction-coil, and this is in the bridge. With very long circuits should any of the origi nal currents penetrate beyond the repeater into the receivlng side of the circuit they are of insuflicient power to reach the distant station or receiver. The coil 0 because it acts Without creating a. lagging-current cannot produce any reacting interference with the retransmitted currents. 4

My invention as embodied in the above-described arrangement is so adaptable togeneral service conditions that it maybe installed not only in fixed relation to a circuit, as is the present practice for extending the distance or power of transmission, but may be installed to be utilized or operated bythe line-operators togreat advantage and in a very flexible Way with. reference to various circuit conditions desirable'to be connected together for repeater service and will relieve theoperators from taking and repeating mes-.

sages,.as is frequently done. The retransmission will have greater urity and volume than heretofore, as the full action of the. repeated currents will pass to the lines, because there is no balancing apparatus or artificial circuit conditions nor line-coils to absorb a portion of the renewed currents.

In the above-described apparatus I prefer to-employ in connection with the receiving upon the repeating-receiver, the repeater apparatus operating to reproduce only such transforming-current effects as may be flowing in the line-circuit, and thus in turn causing the transmitter to. furnish reinforced currents of such effects only, and thereby preventing local action or howling and reactive efiects upon the repeater from reinduced or out-of-phase currents. I

What I claim, and desire to secure by Letters Patent, is i 1.-A telephone repeater system comprisingtwo lines, or two sections forming ,a through-circuit, and their terminal telephones, an induction-coil joining said lines or sections at anintermediate point with a telephone-repeater, said repeater embodying a telephonic receiver and transmitter in repeater relation; the juncture between the circuit and the re eater being wholly inductive and operative tor both the received currents andthe reproduced currents, and connected in bridged relation to the through-circuit the secondary being'bridged in the circuit and the primary being connected in the repeater auxiliary circuit, said auxiliary circuit being divided and also containing a battery, the receiver-transmitter, and means for rendering the receiver inert to its transmitter-currents and sensitive to the received currents from the line. Y

2. The combination in a relay for telephone-currents, of a receiver and transmitter in relay relation, a battery for supplying the relaying-currents, means for renderin the receiver operative only by the induced cur rents froin the line, all in inductive brid ed relation to the line, said inductive relation being common for the receiving and transmittlng currents, and means to prevent reactive currents from afiecting the repeater.

3. In atelephone repeater system, a repeater apparatus, a'main-line circult connect- .ed through without'repeating or induction coils being included therein for the repeater,

a bridge across said line, an induction-coilin said bridge, the repeater being connected to the line bymeans of the secondary of the induction-coil, the repeater receiving and transmitting elements being in circuit with the primary of'said coil.

4; In a telephone-repeater, twin local ch;-

.cuits embraclng a current-supply, and "a-' transmitter in repeater relation to a receiver,

together with means for operating the re'- @eiver f eraa tr sm tt rtte he 1,i

, circuits constituting the medium for-receiv- Jidl Wi G Y H ing from and sending to the line-circuits both, a te ep repeater, .a primary or. the weak incoming and the reinforced outgo; 169 circuit'incl d gthe fol owingelem nt ing currents respectively, substantially as to wit'ithel'primary off 'l-[a described A 1 i i i p 9. In a telephone repeater system containing two sections of transmittingline, anin y 1 strument-circuit local theretovand at an in-' erminat, termediate station thereon, means within I a, tron, tran tting and said local circuit for establishing an electrical receivin el I e s ini the circuit at the balance forthe repeater independent of the transmitting and receiving stations on said line balance and for the purpose of preventl es, abridgeiacross the at the repeater ing the creation of reactiveeffects that disterminals, an iinductionscoil winding in said turb the transmission'or distort the formof "ndenser'ineliidedflin the. bridge the originating current, said meansconstitut- 8o ridi'ngnth, 1 rid" f, ing a part of said instrument-circuit and con- M "l v nectedzwith the transmitting-line, and an in- 4 iduction-coil apparatus in, said connection, for'said primary windin a ;said induction-coil'apparatusbeing common zoo dle branchqof said cire connected tothe to both sections of the line. I center" of the" winding, a "bac eryana the, i 10. In a telephone repeater .syster;n, a transmitterincludedin the middle branch or combined receivertransmitter repeating a'pconductor, a split wound receiver .in the cirparatus, a main circuit with transmitting cuit, with its middle terminals connected to, and receiving apparatus at distantpoints rer 2 5 the middleco'nductor:and withitstWar quiring reinforcing operating curre1- t$ 1 at a 9 mainingte'r ected onefleacheo thev repeating-station, a repeatingv local circuit f 'thecornbination inductively connected with said maincircuit e maj'a 'ge de'nse; and containing a source of current'andthe H A e ,otthe It, receiver v circuits of the combined receiver-transmitter- 30 windings as hunt'toQsamefortherea repeating apparatus. ceived mpulss, the 'bat ry impulsesflow- '11. In a telephone-repeater, a twinlocal ing throughthe receiver-windings in opposi-. circuit containing current-supply, receiving tion to effect, neutrality in said receiver to and transmitting elements in repeater relasfaidbattery impulses,ithe, split battery-curtion, together with common means adapted flowingcooperatively inthe two halves tofinductively operate with the line for both i ductio -coil" fand.iin-.f the received and retransmitted currents. duc ng t lses, 1 :thefsec- 12. Iii'a telephone repeater system,'a line ondary c rcu ath transmltter being in'suoh inductively connected with a repeater in a mechaniealjrelati v :tothej receiver as. to be: local repeater-circuit, a receiver and trans: 49 actuated .QI. 1; I mitterln repeater relation, means for pre 1 ,5 .7. In a telephone system, a repeater, a venting said receiver from being responsive; long-distance metallic circuit with no retardto its actuated transmitter efiects, common ing apparatus, such as frepeatingor induc means for the received and retransmitted; tion CQIlS suchcircuit, but'havingabridge; currents to be, relayed from and to the line; orconnecti between'thetw wiresof; said respectively, meansforenergizing the trans-, up eve1y, jaspcm mitter, togeth er with rneansfor avoiding re v br1dge;.,conta1n1 I l acting or blurring efforts inthe renewed curiv. e t '31-?" 'f J I I he: means H I v 113; Thencombinationof a aintelephone c a; d' mittingto said linethe currents recircuit, and a reinforcing or relay apparatus, 1 5 layed' or received" and the reproduced re -i associated therewith, saidrelay comprisi a transmitt d currents respectively from the receiver and, a.transrnittervinsrepeatelf rea -i, tion,.the,rebeiver adaptedto beactedon dif,-.e ,ferentially, a repeating induetion co l .intere,

posed between said, main circuit: and rein-H forcing apparatus,saidcoil having its secondary winding in operative. connection to swimsuit 0 101 i? h m i r and s-Pr e ylwin a a 1' tron a'g'riet, 1n 'saidf ing; split and the,twothalves-differentially. 69 localcrrcrnt, I her ithlasource of'cun 'w oundwithreferenceto each other and con-@ rent and a variable resistance, mediurn com, nected in circuit with both thegreceiver and trolled by the eleetromagnet, means for rentransmitter elements, together with the bat.- dering' the'electro "a'g' 'et"insensitive,. to the, tery forlenergizing the transmitter, the re-. retransmittin ,,andj 'ndfietioiil ceive element having'two windin s throu h 55 coil'con'r. which the battery-current fiows di erential y 13o to produce neutrality of the receiver to the transmitter variations in the local circuit, the

receiver element having one Winding shunted 1 with a condenser to render it sensitive to the received impulses, and all the currents flowing through the s lit primary of the repeating induction-coi cooperatively and said coil acting to transmit inductively both the incoming and outgoing currents for the relay.

14. A telephone ing secondary and primary portions, the secondary portion consisting of the line-circuit having a bridged connection, a repeating induction-coil, the bridged connection includ ing the secondary of the repeating inductioncoil, and a condenser, the primary portion of repeater system embodysaid system consisting of the primary of the f induction-coil in local circuit with a battery, a repeater receiver-transmitter, and means to render the system sensitive to induced re ceived currents from the line but insensitive l to its local self-action, the inductive effects 1 between the repeater and the line-circuit being Wholly transmitted through the said rcpeating induction-coil.

In testimony whereof I aflix my signature in presence of two Witnesses.

NATHANIEL G. WARTH.

lVitnesses SAMUEL W. LATHAM, ALICE B. CooK. 

